1. Technical Field
The present invention relates to a detection apparatus, method, and program. The present invention particularly relates to a detection apparatus, method, and program that are suitable for use in detecting a state of power in a facility equipped with a private power generation apparatus.
2. Related Art
Along with the widespread use of solar power generation systems and the start of buyback programs for excess power produced from solar power generation systems in recent years, there is a growing need for regular household people to know the amount of power generated by their solar power generation system, the amount of power sold (excess power) from the solar power generation system, the amount of power purchased from a commercial power supply, the amount of power consumed in their house, and the like.
Conventionally, methods have been proposed to determine whether a private power generation apparatus such as a solar power generation system is in a state in which the solar power generation system is supplying excess power to a commercial power supply to sell the power (hereinafter, referred to as a “power selling state”) or in a state in which the solar power generation system is purchasing power by receiving supply of power from the commercial power supply (hereinafter, referred to as a “power purchasing state”) (see, for example, Patent Documents 1 to 3). According to the inventions disclosed in Patent Documents 1 to 3, whether the solar power generation system is in the power purchasing state or in the power selling state is determined by measuring voltage and current of a power line extending from the commercial power supply, calculating power from the measured voltage and current, and detecting the power flow direction based on whether the calculated power is positive or negative.    Patent Document 1: JP 2004-279321A    Patent Document 2: JP 2004-297959A    Patent Document 3: JP H11-225440A